"It's doing as well as we had hoped," said aquarium spokesman Ken Peterson. "We're going to be tagging and putting it back into the bay."
The news marks the aquarium's third failure with the elegant but difficult species. Blue sharks were planned as a feature attraction of the aquarium's million-gallon Outer Bay exhibit, which opened in 1996. But two blue sharks the aquarium hoped to display in the $57 million exhibit died shortly before its debut.
The latest blue shark, a 7 1/2 foot (was 2.32 m), 125-pound male (was 53.4 kg) was captured two weeks ago (27 Aug. 1998) in Monterey Bay and added to the Outer Bay tank, where it joined tuna, sunfish and smaller soupfin sharks. The aquarium announced its addition the following Monday.
But abrasion on the shark's nose from brushing the tank led curators to concerns for the animal's health, Peterson said. Similar scuffs had been blamed for the death of the first blue shark.
"It's been eating well, but it's having trouble navigating around the exhibit," Peterson said. "As long as the shark's in good health, now is the time to release it."
The aquarium will release the shark this morning after giving it a tag, which will help biologists study the species' habits, Peterson said. If the shark is recaptured, the tag will identify it and shoe how far it traveled.
The blue shark, an open-water species named for its cobalt color, is notoriously difficult to keep in captivity. The New Jersey State Aquarium holds the record of seven months for keeping a blue shark alive in a tank. No other aquarium has one on display.
Aquarium officials were so doubtful of their ability to keep their latest blue shark for long that they declined to name it and urged visitors to come quickly for a look. They said they would release the animal at the first sign of stress.
The aquarium isn't giving up its dream of displaying open-water sharks, Peterson said. But they don't expect another blue shark anytime soon.
"I don't know if they'll go for blues again this year," Peterson said.